Daniel K. Resnick

The natural history of cervical spondylotic myelopathy

OBJECTnThe objective of this systematic review was to use evidence-based medicine to delineate the natural history of cervical spondylotic myelopathy (CSM) and identify factors associated with clinical deterioration.nnnMETHODSnThe National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to the natural history of CSM. Abstracts were reviewed and studies meeting the inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I-III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons and the Congress of Neurological Surgeons.nnnRESULTSnThe natural history of CSM is mixed: it may manifest as a slow, stepwise decline or there may be a long period of quiescence (Class III). Long periods of severe stenosis are associated with demyelination and may result in necrosis of both gray and white matter. With severe and/or long lasting CSM symptoms, the likelihood of improvement with nonoperative measures is low. Objectively measurable deterioration is rarely seen acutely in patients younger than 75 years of age with mild CSM (modified Japanese Orthopaedic Association scale score > 12; Class I). In patients with cervical stenosis without myelopathy, the presence of abnormal electromyography findings or the presence of clinical radiculopathy is associated with the development of symptomatic CSM in this patient population (Class I).nnnCONCLUSIONSnThe natural history of CSM is variable, which may affect treatment decisions.

Cervical surgical techniques for the treatment of cervical spondylotic myelopathy.

OBJECTnThe objective of this systematic review was to use evidence-based medicine to compare the efficacy of different surgical techniques for the treatment of cervical spondylotic myelopathy (CSM).nnnMETHODSnThe National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to anterior and posterior cervical spine surgery and CSM. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I-III). The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons.nnnRESULTSnA variety of techniques have improved functional outcome after surgical treatment for CSM, including anterior cervical discectomy with fusion (ACDF), anterior cervical corpectomy with fusion (ACCF), laminoplasty, laminectomy, and laminectomy with fusion (Class III). Anterior cervical discectomy with fusion and ACCF appear to yield similar results in multilevel spine decompression for lesions at the disc level. The use of anterior plating allows for equivalent fusion rates between these techniques (Class III). If anterior fixation is not used, ACCF may provide a higher fusion rate than multilevel ACDF but also a higher graft failure rate than multilevel ACDF (Class III). Anterior cervical discectomy with fusion, ACCF, laminectomy, laminoplasty, and laminectomy with arthrodesis all provide near-term functional improvement for CSM. However, laminectomy is associated with late deterioration compared with the other types of anterior and posterior surgeries (Class III).nnnCONCLUSIONSnMultiple approaches exist with similar near-term improvements; however, laminectomy appears to have a late deterioration rate that may need to be considered when appropriate.

Cervical laminoplasty for the treatment of cervical degenerative myelopathy.

OBJECTnThe objective of this systematic review was to use evidence-based medicine to examine the efficacy of cervical laminoplasty in the treatment of cervical spondylotic myelopathy (CSM).nnnMETHODSnThe National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to cervical laminoplasty and CSM. Abstracts were reviewed and studies meeting the inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I-III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons and Congress of Neurological Surgeons.nnnRESULTSnCervical laminoplasty has improved functional outcome in the setting of CSM or ossification of the posterior longitudinal ligament. Using the Japanese Orthopaedic Association scale score, approximately 55-60% average recovery rate has been observed (Class III). The functional improvement observed after laminoplasty may be limited by duration of symptoms, severity of stenosis, severity of myelopathy, and poorly controlled diabetes as negative risk factors (Class II). There is conflicting evidence regarding age, with 1 study citing it as a negative risk factor, and another not demonstrating this result.nnnCONCLUSIONSnCervical laminoplasty is recommended for the treatment of CSM or ossification of the posterior longitudinal ligament (Class III).

Clinical prognostic indicators of surgical outcome in cervical spondylotic myelopathy.

OBJECTnThe objective of this systematic review was to use evidence-based medicine to assess whether clinical factors predict surgical outcomes in patients undergoing cervical surgery.nnnMETHODSnThe National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to clinical preoperative factors. Abstracts were reviewed, and studies that met the inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I-III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons.nnnRESULTSnPreoperative sensory-evoked potentials may aid in providing prognostic information in selected patients in whom clinical factors do not provide clear guidance (Class II). Age, duration of symptoms, and preoperative neurological function may commonly affect outcome (Class III).nnnCONCLUSIONSnAge, duration of symptoms, and preoperative neurological function should be discussed with patients when surgical intervention for cervical spondylotic myelopathy is considered. Preoperative sensory-evoked potentials may be considered for patients in whom clinical factors do not provide clear guidance if such information would potentially change therapeutic decisions.

Laminectomy and fusion for the treatment of cervical degenerative myelopathy

OBJECTnThe objective of this systematic review was to use evidence-based medicine to examine the efficacy of cervical laminectomy and fusion for the treatment of cervical spondylotic myelopathy (CSM).nnnMETHODSnThe National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to cervical laminectomy, fusion, and CSM. Abstracts were reviewed, after which studies that met the inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Class I-III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations which contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer-review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons.nnnRESULTSnCervical laminectomy with fusion (arthrodesis) improves functional outcome in patients with CSM and ossification of the posterior longitudinal ligament (OPLL). Functional improvement is similar to laminectomy or laminoplasty for patients with CSM and OPLL. In contrast to laminectomy, cervical laminectomy with fusion it is not associated with late deformity (Class III).nnnCONCLUSIONSnLaminectomy with fusion (arthrodesis) is an effective strategy to improve functional outcome in CSM and OPLL.

Electrophysiological monitoring during surgery for cervical degenerative myelopathy and radiculopathy.

OBJECTnThe objective of this systematic review was to use evidence-based medicine to examine the diagnostic and therapeutic utility of intraoperative electrophysiological (EP) monitoring in the surgical treatment of cervical degenerative disease.nnnMETHODSnThe National Library of Medicine and Cochrane Database were queried using MeSH headings and key words relevant to cervical spine surgery and EP monitoring. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I-III). The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons.nnnRESULTSnThe reliance on changes in EP monitoring as an indication to alter a surgical plan or administer steroids has not been observed to reduce the incidence of neurological injury during routine surgery for cervical spondylotic myelopathy or cervical radiculopathy (Class III). However, there is an absence of study data examining the benefit of altering a surgical plan due to EP changes.nnnCONCLUSIONSnAlthough the use of EP monitoring may serve as a sensitive means to diagnose potential neurological injury during anterior spinal surgery for cervical spondylotic myelopathy, the practitioner must understand that intraoperative EP worsening is not specific-it may not represent clinical worsening and its recognition does not necessarily prevent neurological injury, nor does it result in improved outcome (Class II). Intraoperative improvement in EP parameters/indices does not appear to forecast outcome with reliability (conflicting Class I data).

Functional outcomes assessment for cervical degenerative disease.

OBJECTnThe objective of this systematic review was to use evidence-based medicine to identify valid, reliable, and responsive measures of functional outcome after treatment for cervical degenerative disease.nnnMETHODSnThe National Library of Medicine and Cochrane Database were queried using MeSH headings and key words relevant to functional outcomes. Abstracts were reviewed after which studies meeting inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I-III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons.nnnRESULTSnMyelopathy Disability Index, Japanese Orthopaedic Association scale, 36-Item Short Form Health Survey, and gait analysis were found to be valid and reliable measures (Class II) for assessing cervical spondylotic myelopathy. The Patient-Specific Functional Scale, the North American Spine Society scale, and the Neck Disability Index were found to be reliable, valid, and responsive (Class II) for assessing radiculopathy for nonoperative therapy. The Cervical Spine Outcomes Questionnaire was a reliable and valid method (Class II) to assess operative therapy for cervical radiculopathy.nnnCONCLUSIONSnSeveral functional outcome measures are available to assess cervical spondylotic myelopathy and cervical radiculopathy.

Anterior cervical surgery for the treatment of cervical degenerative myelopathy.

OBJECTnThe objective of this systematic review was to use evidence-based medicine to examine the efficacy of anterior cervical surgery for the treatment of cervical spondylotic myelopathy (CSM).nnnMETHODSnThe National Library of Medicine and Cochrane Database were queried using MeSH headings and key words relevant to anterior cervical surgery and CSM. Abstracts were reviewed, and studies meeting inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I-III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons.nnnRESULTSnMild CSM (modified Japanese Orthopaedic Association [mJOA] scale scores > 12) responds in the short term (3 years) to either surgical decompression or nonoperative therapy (prolonged immobilization in a stiff cervical collar, low-risk activity modification or bed rest, and antiinflammatory medications) (Class II). More severe CSM responds to surgical decompression with benefits being maintained a minimum of 5 years and as long as 15 years postoperatively (Class III).nnnCONCLUSIONSnTreatment of mild CSM may involve surgical decompression or nonoperative therapy for the first 3 years after diagnosis. More severe CSM (mJOA scale score <or= 12) should be considered for surgery depending upon the individual case. The shortcomings of this systematic review are that the group was not able to determine whether an mJOA scale score of 12 was indicative of a more severe CSM disease course, and whether patients who received nonsurgical treatment for 3 years had a significant probability for clinical deterioration after that time point.

Preoperative patient selection with magnetic resonance imaging, computed tomography, and electroencephalography: does the test predict outcome after cervical surgery?

OBJECTnThe objective of this systematic review was to use evidence-based medicine to assess whether preoperative imaging or electromyography (EMG) predicts surgical outcomes in patients undergoing cervical surgery.nnnMETHODSnThe National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to the preoperative imaging and EMG. Abstracts were reviewed after which studies meeting inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I-III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons.nnnRESULTSnPreoperative MR imaging and CT myelography are successful in confirming clinical radiculopathy (Class II). Multilevel T2 hyperintensity, T1 focal hypointensity combined with T2 focal hyperintensity, and spinal cord atrophy each convey a poor prognosis (Class III). There is conflicting data concerning whether focal T2 hyperintensity or cervical stenosis are associated with a worse outcome. Electromyography has mixed utility in predicting outcome (Class III).nnnCONCLUSIONSnMagnetic resonance imaging or CT myelography are important for preoperative assessment. Magnetic resonance imaging may be helpful in assessing prognosis, whereas EMG has mixed utility in assessing outcome.

Introduction and methodology: guidelines for the surgical management of cervical degenerative disease

In March 2006, the Joint Section on Disorders of the Spine and Peripheral Nerves of the American Association of Neurological Surgeons and Congress of Neurological Surgeons compiled an expert group to perform an evidence-based review of the clinical literature on management of cervical degenerative spine disease. This process culminated in the formation of the Guidelines for the Surgical Management of Cervical Degenerative Disease. The purpose of the Guidelines was to address questions regarding the therapy, diagnosis, and prognosis of cervical degenerative disease using an evidence-based approach. Development of an evidence-based review and recommendations is a multitiered process. Typical guideline development consists of 5 processes: 1) collection and selection of the evidence; 2) assessment of the quality and strength of the evidence; 3) analysis of the evidentiary data; 4) formulation of recommendations; and 5) guideline validation. This manuscript details the methodology in compiling the Guidelines for the Surgical Management of Cervical Degenerative Disease.